Ethnobotanical Leaflets 10: 342-349. 2006.

Piscicidal Plants of Nepal: Checklist, Ethnobotanical Uses and Indigenous Practices

Ananda R. Joshi* and Kunjani Joshi**

*Former Director General, SACEP, Colombo, Sri Lanka

**Harvard University Herbaria, USA

Email: [email protected], [email protected]

Issued 22 December 2006

Introduction

               Fish catching with the aid of plants and their parts is an ancient practice. The rural communities of Nepal collect piscicidal plants and their parts from various habitats, such as forest, scrub, grassland, cultivated fields, wetlands and riverbanks and use them following traditional methods and practices to stupefy fish. However, at present, the piscicidal plants and their ethenobotanical information are being eroded as a result of haphazard exploitation of resources, habitat destruction and land use change (Joshi and Joshi, 2005). The loss of traditional knowledge within cultures undergoing rapid change is just as irreversiable as the loss of species (Joshi and Joshi, 2004). Hence, priority should be given to document the useful plants and their uses along with indigenous knowledge, methods and practices. Though some ethnobotanical initiatives related to the piscicidal plants have already taken (Bhandary and Shrestha, 1982; Joshi and Joshi, 2005a; Karki and Rai, 1982; Regmi and Karna, 1989; Manandhar, 1989), less priority has been given to the systematic and comprehensive enumeration of these species and their conservation in an integrated manner. Therefore, an attempt has been made to document and enumerate the piscicidal plants with exising traditional uses and practices.

 Study Areas and Methods

               The ethnobotanical information were collected from the villages of the various districts of Nepal. The complex geomorphology, climatic variations and other physical characteristics make these villages rich in diverse habitats with useful species including the piscicidal plants. These areas are inhabited by different ethnic tribes, who have rich knowledge on ethnobotanical information. Ethnobotanical information was collected using various techniques and also verified with secondary sources.

 Enumeration of Species

               The plant species, which are reported to have piscicidal effects, are enumerated in Table 1. Seventy-nine piscicidal plants belonging to 35 families are arranged alphabetically by genus–species, family followed by local names, and parts of the plant used. Among the documented species, the family Fabaceae was most frequently represented with a total of 11 species, followed by Polygonaceae 7, Euphorbiaceae 6, Ateraceae 5 and others with less than 5 species.

 Indigenous Knowledge and Practices

            The local people have excellent knowledge of species identification, usefulness of the plants and traditional practices. Though the main occupation of villagers of the study areas is agriculture, fishing is an alternative source of income. They collect fish for food and also for sale in nearby markets. Maghi tribes are mainly involved in fishing occupation and used to utilize all parts or a certain part of the plant as fish poison. Sometimes for catching fish from rivers, the flow of water is checked either by erecting a temporary wall of mud and stones or by diverting the water current into small temporary ponds. The plant or a plant part is crushed and thrown into the water. The fish poison makes the fish float in a stupefied state and come to the surface of water from where they are easily captured.

            According to the information of the local people, some species are preferred for fish poison and frequently used. These species are Agave cantala, Buddleja asiatica, Buddleja paniculata, Engelhardia spicata, Euphorbia royleana, Juglans regia, Persicaria hydropiper, and Sapium insigne.

Table 1. Piscicidal plants of Nepal.

Strategies for Sustainable Management

The following strategies are recommended for sustainable management of useful plant diversity.

1.      Inventory, Chemical Screening and Documentation of the Species

            Many parts of the biogeographical areas of the country have still remained unexplored. Hence, it is strongly recommended that major thrust should be given to an intensive inventory and documentation of piscicidal plants and their products. Emphasis should also be given to analyse chemical components of the plants and the parts which are used to stupefy fishes. A more systematic investigation of some of these plants may lead to the discovery of new economically useful products.

2. Documentation of Traditional information, methods and practices

          The rural people have developed unique indigenous knowledge related to the uses of plant resources due to constant association with the forests. These existing valuable information are needed to be documented before lost or disappeared. As there is lake of the documentation system, priority should be given to develop a system for the systematic recording of the information related to the ethnobotanical uses and indigenous knowledge of the species.

 3. Conservation of useful species and their habitats

            Though forests, scrubs, grasslands and waste lands are the major habitats of the pecicidal plants, most of them appear to be restricted only to shaded forest habitats. An obvious conclusion that can be drawn from this picture is that deforestation and habitat destruction due to land use change would pose a serious threat to the species. Even without tree-removal, extensive grazing of domestic animals in the forests can be damaging to some species. When questioned about the changing status of the existing plants, our respondents listed some important species such as Coriaria nepalensis, Sapium insigne and Zanthoxylum armatum which have also declined in abundance during the last decade. The trend of decline of abundance of the useful species shows that action for conservation is urgently needed. Hence, efforts should be directed to formulate and implement appropriate strategies and programs related to the conservation and sustainable uses of these plants and their products taking consideration of the needs of the people.

Acknowledgements

            The authors are thankful to the inhabitants of the study areas for their kind cooperation and help during the field survey. Thanks are due to Dr. John F. Edington, University of Wales, U.K. for his guidance and encouragement, and to Dr. S. K. Jain, Founder and Ex-Director, Institute of Ethnobiology, Lucknow, India for encouragement.

References

Bhandary, H.R. and Shrestha, P. 1982. Ethnobotanical exploration of the poisonous plants of Kathmandu Valley. Proc. First Nation. Sci. Tech. Cong. National Council of Science and Technology, Kathmandu, Nepal. pp.89-97.

Bhandary, H.R. and Shrestha, P. 1999. Poisonous plants of Kathmandu Valley. In: T.C. Majupuria and R.K. Majupuria (eds.), Nepal-Nature’s Paradise, (), M. Devi, Gwalior, India. pp.151-158

Chaudhary, R.P., Nepal, M., Gupta, V.N.P. and Vetaas, O.R. 2002. Traditional use of plants by the indigenous peoples of makalu-barun region, eastern Nepal. In : R.P. Chaudhary, B.P. Subedi, O.R. Vetaas and T.H. Aase (eds.), Vegetation and Society: Their Interaction in the Himalayyas, Tribhuvan University, Nepal and University of Bergen, Norway, pp83-97.

Chhetri, R.B. and Joshi, Rekha 2002. Ethnobotany of non-timber forest product in Langtang National Park, Nepal. Proceeding of International Seminar on Mountains – Kathmandu. March 6-8, 2002, RONAST, Kathmandu, Nepal. pp 469-472.

Dangol, D.R. 2000-2001. Aquatic plant resources and their uses : observation from Beesh Hazar Lake, Chitwan. J. Inst. Agric. Anim. Sci. 21-22, 119-133.

Dangol, D.R. and Gurung, S.B. 1999. Ethnobotanical study of Darai tribe in Chitwan District, Nepal, Proceeding of III National conference on Science and Technology, March 8-11, 1999, RONAST, Nepal, pp. 1194-1213.

Ghimere, S.K., Shrestha, A.K., Shrestha, K.K. and Jha, P.K. 2000. Plant resources use and human impact around Royle Bardia National Park, Nepal. J. Nat. Hist. Mus. 19, 3-26.

Gurung, S.B., Dangol, D.R. and Bhandary, A. 1999, Preliminary study on plant communities of forest ecosystem in Chitwan, Central Nepal. Proceeding of III National conference on Science and Technology, March 8-11, 1999, RONAST, Nepal, pp1571-1578.

Joshi, A.R. 1988. A Study of the Environmental Relationship of Certain Village Communities in the Central Development Region of Nepal, Ph.D. Thesis, University of Wales, Cardiff, UK.

Joshi, A.R. and Joshi, Kunjani, 2005a. Piscicidal plants of Bagmati watershed , Nepal: Indigenous practices. Ethnobotany 17, 184-186.

Joshi, A. R. and Joshi, Kunjani 2005b. Non-Timber forest Products of Bagmati and Langtang watershed, Nepal : raw materials of plant orign and their indigenous uses. Journal of Non-Timber Forest Products 12(2), 76-86.

Joshi, Kunjani 1991. The uses of wild plants by local communities in the mountainous region of Nepal, Mountain Environment and Development 1(2), 43-52.

Karki, K.B. and Rai, A.K. 1982. Observations on the effectiveness of some local plants used as fish poison, Proc. First Nation. Sci. Tech. Cong., National Council of Science and Technology, Kathmandu, Nepal. pp. 270-273.

Manandhar, N.P. 1989. Ethnobotanical notes on some Piscicidal plants of Nepal. Ethnobotany 1, 57-59.

Manandhar, N.P. 2002. Plant and People of Nepal. Timber Press Inc., Portland, USA

Mandar, L.N. and Chaudhary, R.P. Medicinal plants and their traditional use by tribal people of Saptari District, Nepal. In : Bhuju, D.R., Sharma, A.P., Prashad, B.N., Joshi, K.K., Rajbhandary,K.R., Jha, P.K., Joshi, S.D. and Karmachrya, S.B. (eds.), Proceedongs of First National Botanical Conference, August 11-12,1992, Nepal Botanical Society, Kathmandu,

    Nepal, pp33-42.

Regmi, P.P. 1982. The unexploited plant potentials of Nepal. Proc. First Nation. Sci. Tech. Cong., National Council of Science and Technology, Kathmandu, Nepal. pp. 153-167.

Regmi, P.P. and Karna, P.L. 1989. Weeds and other plants of pesticidal values in Nepal. Proceedings of National Conference on Science and Technology, April 24-29, 1988., RONAST, Kathmandu, Nepal. pp.161-173.

Siwakoti, M. and Siwakoti, S. 2003. Ethenomedicinal Uses of plants among the Limbu of Morang District, Nepal. Ecoprint 59 (1), 79-84.

Siwakoti, M., Shivakoti, K.P., Karki, B. and Siwakoti, S. 2005. Ethnobotanical uses of plants among Rajbansi and Dhimal ethnic communities of Eastern Nepal. J. Nat. Hist. Mus. 22, 41-56.